Calculation method of the direction from the sun to the mountain

From the sun to the mountain, it means that the sun runs to a certain direction of the twenty-four mountains. The sun we see rises in the east and sets in the west every day. The sun seems to be from east to west. In fact, it is because the earth rotates from west to east that it gives us the feeling of rising east and setting west.

The orbit of the sun in the sky is called the ecliptic, and its apparent motion is about one circle from west to east every day. Returning to the original place after a year is called a year, and the vernal equinox happens to be the beginning of the palace. The palace is 30 degrees, the front 15 degree is Xushan, and the back 15 degree is Xushan. According to this calculation, the vernal equinox reaches Xushan.

As for the direction of arrival, it is simpler. The small opposite side is the direction, Zishan must be at noon, Renshan must be in three directions, and the sun shines in three directions. When the sun reaches Zi Shan, Chen Shenshan will also shine.